I am Grade 13 like you. I've regreted the fact that I wasted my time( 8 monthCovid break) and promised my self I wont repeat that again. So what I want to say is put your time to something that is meaningful, something that is going to help you in the future. It might be different for everyone but try to find what you love, try new things out, learn some skills that will help you in the future, Read Books... there are tons of things you could do but please learn to manage your time and put it to something that you wont regret.